Frozen sauce is typically used in frozen ready meals or in catering services. Conventionally, the sauce is either dosed directly onto the meal and frozen together with it, or frozen into blocks separately. Frozen sauce may also be prepared in pellet form which is then used in meals made of individual frozen cubes of meat and vegetables. Such meals are usually prepared by pan-frying.
The prior art sauce pellets or portions are frozen in molds or by dosing droplets of sauce onto a very cold, i.e., below freezing temperature, surfaces. When freezing pellets in molds, substantial work is involved in filling, emptying and cleaning the molds. Freezing of sauce pellets by dosing onto a frozen surface results in flat and irregular pellet shapes.
When providing a frozen sauce it is important that once the sauce is thawed, it remains substantially unchanged compared to unfrozen sauce. For example, the viscosity of the sauce should not substantially change. The amount of starch in the sauce is determining for the viscosity of the sauce. If the sauce is subjected to too severe mechanical contact, the starch molecules will be damaged.
It is known to freeze liquid food products in ice-cream freezers, a process which is used in sorbet and ice-cream production. Ice-cream freezers are freezers that have cooling heat exchange surfaces with scrapers moving the food product to and from the cooling surfaces. Such freezers may not be suitable for the freezing of certain types of sauce as the freezing and scraping process can damage starch molecules in the sauce, resulting in a thawed sauce which has a lower viscosity than a similar sauce that has not gone through the ice-cream freezing process. This can require an extra step where starch must be added to the thawed sauce to increase the viscosity to desired levels.
The use of ice-cream freezers with scrapers may also be undesirable for sauces that contain particles or lumps of vegetables, meat or fish, because the scrapers provide a milling action that can produce more finely distributed particles which can result in a color change of the sauce.
It is an aim of the invention to provide a method for freezing pellets of sauce in a manner which does not substantially damage the starch molecules so that the re-heated sauce has substantially the same consistency as the sauce prior to freezing.